Hearing impairment, to a greater or lesser extent, affects more than 30 million people in the United States, according to the American Academy of Audiology. Hearing impairment can affect its victim in a variety of ways, such as a reduced comprehension of conversation or spoken words, or reduced ability to hear and enjoy music.
Many technologies have been developed to reduce the impact of hearing impairment on those who suffer from it. These technologies include a variety of hearing aids, diagnostic techniques and related devices.
One device for improving the comprehension of an audio signal by a hearing impaired person is the LINX COIL™. This device has been described in the following commonly-owned patent documents: Provisional Patent Application 60/837,752 filed Aug. 15, 2006, patent application Ser. No. 11/188,519 filed Jul. 25, 2005, and patent application Ser. No. 10/864,691 filed Jun. 9, 2004. The Linx device, described more fully below, alters an audio signal in a variety of ways to provide improved clarity and comprehension for hearing-impaired listeners.
Diagnostic techniques allow quantification and characterization of the hearing impairment suffered by any individual person. One common diagnostic technique within audiology involves the production of an audiogram. An audiogram is typically created by testing a subject person with an audiometer.
An audiometer presents controlled acoustic stimuli to the subject through a set of headphones or other transducers. The tonal stimuli vary in frequency across the spectrum of sound normally within the range of human hearing. The subject indicates, through a feedback device, the sounds which are audible to the subject.
The audiometer records the lowest level of sounds to which the subject responds at each of the frequencies. The resulting chart provides a visual representation of the hearing loss of the test subject across frequency. Frequencies at which the test subject required louder sound levels before the signal was audible indicate frequencies at which the test subject has suffered hearing loss.
Audiometers may include multi-band equalizers and may provide modes that simulate a hearing aid or simulate hearing loss by altering the relative levels of frequency bands within a test signal.